[PATCH bpf V10 1/6] selftests/bpf: xdp_hw_metadata remove bpf_printk and add counters

From: Jesper Dangaard Brouer
Date: Wed Apr 12 2023 - 15:49:47 EST


The tool xdp_hw_metadata can be used by driver developers
implementing XDP-hints metadata kfuncs.

Remove all bpf_printk calls, as the tool already transfers all the
XDP-hints related information via metadata area to AF_XDP
userspace process.

Add counters for providing remaining information about failure and
skipped packet events.

Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
---
.../testing/selftests/bpf/progs/xdp_hw_metadata.c | 36 ++++++++++++--------
tools/testing/selftests/bpf/xdp_hw_metadata.c | 4 ++
2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
index 4c55b4d79d3d..0687d11162f6 100644
--- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
@@ -12,6 +12,10 @@ struct {
__type(value, __u32);
} xsk SEC(".maps");

+__u64 pkts_skip = 0;
+__u64 pkts_fail = 0;
+__u64 pkts_redir = 0;
+
extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
__u64 *timestamp) __ksym;
extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx,
@@ -26,7 +30,7 @@ int rx(struct xdp_md *ctx)
struct udphdr *udp = NULL;
struct iphdr *iph = NULL;
struct xdp_meta *meta;
- int ret;
+ int err;

data = (void *)(long)ctx->data;
data_end = (void *)(long)ctx->data_end;
@@ -46,17 +50,20 @@ int rx(struct xdp_md *ctx)
udp = NULL;
}

- if (!udp)
+ if (!udp) {
+ __sync_add_and_fetch(&pkts_skip, 1);
return XDP_PASS;
+ }

- if (udp->dest != bpf_htons(9091))
+ /* Forwarding UDP:9091 to AF_XDP */
+ if (udp->dest != bpf_htons(9091)) {
+ __sync_add_and_fetch(&pkts_skip, 1);
return XDP_PASS;
+ }

- bpf_printk("forwarding UDP:9091 to AF_XDP");
-
- ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
- if (ret != 0) {
- bpf_printk("bpf_xdp_adjust_meta returned %d", ret);
+ err = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
+ if (err) {
+ __sync_add_and_fetch(&pkts_fail, 1);
return XDP_PASS;
}

@@ -65,20 +72,19 @@ int rx(struct xdp_md *ctx)
meta = data_meta;

if (meta + 1 > data) {
- bpf_printk("bpf_xdp_adjust_meta doesn't appear to work");
+ __sync_add_and_fetch(&pkts_fail, 1);
return XDP_PASS;
}

- if (!bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp))
- bpf_printk("populated rx_timestamp with %llu", meta->rx_timestamp);
- else
+ err = bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp);
+ if (err)
meta->rx_timestamp = 0; /* Used by AF_XDP as not avail signal */

- if (!bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash))
- bpf_printk("populated rx_hash with %u", meta->rx_hash);
- else
+ err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash);
+ if (err)
meta->rx_hash = 0; /* Used by AF_XDP as not avail signal */

+ __sync_add_and_fetch(&pkts_redir, 1);
return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
}

diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 1c8acb68b977..3b942ef7297b 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -212,7 +212,9 @@ static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd)
while (true) {
errno = 0;
ret = poll(fds, rxq + 1, 1000);
- printf("poll: %d (%d)\n", ret, errno);
+ printf("poll: %d (%d) skip=%llu fail=%llu redir=%llu\n",
+ ret, errno, bpf_obj->bss->pkts_skip,
+ bpf_obj->bss->pkts_fail, bpf_obj->bss->pkts_redir);
if (ret < 0)
break;
if (ret == 0)